DD2 enrollment
Enrollment in DD2 involves filling out a questionnaire and providing urine and blood samples. All Danish residents older than 18 years of age diagnosed with diabetes within the last 2 years are eligible for inclusion in DD2 (previously, a longer diabetes duration was allowed). Individuals may either sign up online and be contacted later, or be approached by practice personnel during routine care. The individual will receive an e-mail with a link to WebPatient, where a few questions should be filled out before the questionnaire will be sent to the practice. Hereafter, a DD2 examination will take place, where additional questions will be answered (e.g., a clinically assessed date of diabetes onset) along with a physical examination (e.g., to measure weight, hip and waist circumference, and resting heart rate). The examination also involves a urine sample (morning urine) and a blood sample (fasting).
Enrollment can either take place in the general practice or in the outpatient clinic. For further information about the enrollment, please see the official DD2 website (Danish): Patient information and Instructions and questionnaires.
The first individual was enrolled in DD2 in November 2010. By November 2023 the DD2 cohort included a total of N=12,098 individuals. The enrollment during the period from November 2010 to April 2023, including N=11,369 individuals, is illustrated in the 2024 cohort paper (Kristensen et al. (2024)).
Overview of enrollment in the DD2 cohort from November 2010 to April 2023. The plots show the cumulative and annual number of enrolled individuals.
The N=11,369 individuals enrolled by April 2023, had a median age at enrollment of 61 years (IQR 53–69 years) and 41% were women (Kristensen et al. (2024)). Median diabetes duration at time of enrollment was 1.3 years (IQR 0.4–2.9 years) and 87% were already prescribed with glucose-lowering treatment at the time of enrollment (Kristensen et al. (2024)).
For more information about the enrollment and data collection, please contact DD2. Some of the general DD2 documents can also be downloaded here (Danish, downloaded 12 January 2024):